Asphalt concrete is a composite material of asphalt and concrete and is importantly used in construction of roads, etc. However, because such asphalt concrete should be replaced after a predetermined period of time, social problems for treating waste asphalt concrete occur. There is thus a high interest in recycling waste asphalt concrete. Asphalt employed in the asphalt concrete is a final residue upon refining of crude oil and is regarded as a kind of pollutant. Hence, when waste asphalt concrete is discarded on the ground or buried underground, underwater and streams or rivers may be polluted by asphalt contained therein, undesirably incurring serious pollution problems. The waste asphalt concrete is classified as industrial waste, and thorough research into recycling it is ongoing. In this regard, a conventional method of manufacturing regenerated asphalt concrete includes pre-treating waste asphalt concrete through grinding and separation of impurities, heating it using an indirect heating type dryer at 130˜150° C. so as to be stored in a silo, adding a predetermined amount of novel asphalt concrete based on the waste asphalt concrete, and mixing an additive. In the conventional method as above, however, the waste asphalt concrete is not uniformly coated with the additive, and whitening may occur due to oxidation of the waste asphalt concrete. Furthermore, because the asphalt used in paved roads is exposed to air over the course its use, collected waste asphalt concrete inevitably contains partially oxidized aged asphalt. When the oxidized aged asphalt of the waste asphalt concrete is not appropriately treated but is mixed with novel materials and used for road pavement, serious cracking may take place soon after pavement.
Moreover, by virtue of changes in human lifestyles, there are many cases of colored road pavement so as for visual beauty and harmony with the surrounding areas. Such roads make the surrounding areas beautiful and harmonize with the peripheral environment and are thus intended to compliment nature, rather than just being responsible for the easy passage of vehicles and persons.
Accordingly, many attempts are being made to apply a variety of colors in lieu of the conventional asphalt concrete pavement dark gray appearance. With the recent trend of further highlighting the importance of the environment and urban aesthetics, the demand for colored asphalt concrete pavement is increasing. Colored asphalt concrete pavement increases the appearance, and also is utilized in construction of bus lanes, pedestrian crossings, bicycle lanes, etc. by various colors thereof to thereby ensure visual effects so as to be able to increase stability for drivers or pedestrians.
However, conventional colored regenerated asphalt concrete is easily discolored, undesirably deteriorating weather resistance and durability.